Serious adverse events and 30-day hospital readmission rate following elective total knee arthroplasty: a systematic review and meta-analysis

Background Elective total knee arthroplasty (TKA) is a common surgery which has evolved rapidly. However, there are no recent large systematic reviews of serious adverse event (SAE) rate and 30-day readmission rate (30-dRR) or an indication of whether surgical methods have improved. Methods To obtain a pooled estimate of SAE rate and 30-dRR following TKA, we searched Medline, Web of Science, Cochrane Library, and Google Scholar databases. Data were extracted by two authors following PRISMA guidelines. Eligibility criteria were defined prior to a comprehensive search. Studies were eligible if they were published in 2007 or later, described sequelae of TKA with patient N > 1000, and the SAE or 30-dRR rate could be calculated. SAEs included return to operating room, death or coma, venous thromboembolism (VTE), deep infection or sepsis, myocardial infarction, heart failure or cardiac arrest, stroke or cerebrovascular accident, or pneumonia. Results Of 248 references reviewed, 28 are included, involving 10,153,503 patients; this includes 9,483,387 patients with primary TKA (pTKA), and 670,116 patients with revision TKA (rTKA). For pTKA, the SAE rate was 5.7% (95% CI 4.4-7.2%, I-2 = 100%), and the 30-dRR was 4.8% (95% CI 4.3-5.4%, I-2 = 100%). For rTKA, the SAE rate was 8.5% (95% CI 8.3-8.7%, I-2 = 77%), while the 30-dRR was 7.2% (95% CI 6.4-8.0%, I-2 = 81%). Odds of 30-dRR following pTKA were about half that of rTKA (OR 0.57, 95% CI 0.53-0.62%, p < 0.001, I-2 = 45%). Of patients who received pTKA, the commonest SAEs were VTE (1.22%; 95% CI 0.83-1.70%) and genitourinary complications including renal insufficiency or renal failure (1.22%; 95% CI 0.83-1.67%). There has been significant improvement in SAE rate and 30-dRR since 2010 (chi(2) test < 0.001). Conclusions TKA procedures have a relatively low complication rate, and there has been a significant improvement in SAE rate and 30-dRR over the past decade.